Stand alone or system based duct mounted detectors find use in a variety of installations including ventilation and air conditioning ducts which provide fresh air to monitored regions. In such installations, it is useful to monitor concentrations of airborne gases, such as carbon dioxide.
In such ducts, air can be moving in vertical or horizontal directions. Quite apart from the direction of air movement, it is, at times, desirable to orient the detectors, relative to the adjacent region, so that any display devices carried on the detector can be easily read by local personnel.